One of the more invasive geoengineering methods that's been proposed to avert global warming is spraying clouds with seawater to whiten them, reflecting solar radiation. New research presented at the European Geosciences Union meeting urges caution though: Done incorrectly the procedure could actually cause more warming, rather than prevent it.

[The study] concluded that about 70 times more salt would have to be carried aloft than proponents have calculated. And using droplets of the wrong size, she found, could reduce cloud cover rather than enhancing it... "If the particles are too small, they will not brighten the clouds - instead they will influence particles that are already there, and there with be competition between them," she told BBC News.

One of the more invasive geoengineering methods that's been proposed to avert global warming is spraying clouds with seawater to whiten them, reflecting solar radiation. New research presented at the European Geosciences Union meeting urges caution